Sporting opened the scoring in the 31st minute when Opara’s soft header off a feed from Benny Feilhaber floated over goalkeeper Justo Lorente.
Kansas City had several more good chances to get another goal, but didn’t connect until Dwyer broke free in the attacking end off a feed from Aurelien Collin. Dwyer moved to his left and then shot into the opposite end of the net, just picking the far corner past Lorente.
Eric Kronberg picked up the shutout for KC, which outshot Esteli 10-2.
Midfielder Christian Bermudez got the only goal as Club America opened its CONCACAF Champions League play with a 1-0 victory at San Miguelito on Wednesday night.
Bermudez connected in the 23rd minute as the Mexican team outshot the hosts 16-9.
America took the lead in Group 4 of the 24-team tournament. The club has won the CONCACAF title five times.
Meanwhile, the Montreal Impact defeated fellow MLS side San Jose 1-0 behind a first half goal from defender Hassoun Camara. With the victory, Montreal claims three points in Group 5.